With the development of electronic technology, various electronic products have become available, particularly consumer electronic devices, such as tablets, smart phones, laptops, 2-in-1 laptop/tablets, and the like.
To make the electronic devices easy to use, these electronic devices are provided with displays from which users can view the displayed content with ease. When an electronic device is in use, the backlight of the display is usually turned on, and the display is in a bright-screen state. If the electronic device is not in use, the display is turned off for power saving, referred to as a black-screen state. When an electronic device is in use, it can be held or placed by a user in different orientations.